Abstract:
Globe artichoke (Cynara cardunculus var. scolymus; 2n = 2x = 34) is a food crop consumed for its immature flower heads. Traditionally, globe artichoke varietal types are vegetatively propagated. However, seed propagation makes it possible to treat the crop as annual, increasing field uniformity and reducing farmers costs, as well as pathogens diffusion. Despite globe artichoke\'s significant agricultural value and the critical role of heterosis in the development of superior varieties, the production of hybrids remains challenging without a reliable system for large-scale industrial seed production. Male sterility (MS) presents a promising avenue for overcoming these challenges by simplifying the hybridization process and enabling cost-effective seed production. However, within the Cynara genus, genic male sterility has been linked to three recessive loci in globe artichoke, with no definitive genetic mechanism elucidated to date. A 250 offsprings F2 population, derived from a cross between a MS globe artichoke and a male fertile (MF) cultivated cardoon (C. cardunculus var. altilis) and fitting a monogenic segregation model (3:1), was analyzed through BSA-seq, aiming at the identification of genomic regions/genes affecting male sterility. Four QTL regions were identified on chromosomes 4, 12, and 14. By analyzing the sequence around the highest pick on chromosome 14, a cytochrome P450 (CYP703A2) was identified, carrying a deleterious substitution (R/Q) fixed in the male sterile parent. A single dCAPS marker was developed around this SNP, allowing the discrimination between MS and MF genotypes within the population, suitable for applications in plant breeding programs. A 3D model of the protein was generated by homology modeling, revealing that the mutated amino acid is part of a highly conserved motif crucial for protein folding.
摘要:
朝鲜蓟(Cynaracardunculusvar。scolymus;2n=2x=34)是一种因未成熟花头而消耗的粮食作物。传统上,地球朝鲜蓟品种是营养繁殖的。然而,种子繁殖使得可以将作物视为一年生作物,提高田间统一性,降低农民成本,以及病原体扩散。尽管全球朝鲜蓟具有重要的农业价值和杂种优势在优良品种发展中的关键作用,如果没有用于大规模工业种子生产的可靠系统,杂种的生产仍然具有挑战性。雄性不育(MS)为通过简化杂交过程和实现成本有效的种子生产克服这些挑战提供了有希望的途径。然而,在Cynara属中,基因雄性不育与洋蓟中的三个隐性基因座有关,迄今尚未阐明明确的遗传机制。250个后代F2人口,源自MS球形朝鲜蓟和雄性可育(MF)栽培的cardoon之间的杂交(C.cardunculusvar.altilis)并拟合单基因偏析模型(3:1),通过BSA-SEQ分析,旨在鉴定影响雄性不育的基因组区域/基因。在染色体4、12和14上鉴定了四个QTL区域。通过分析14号染色体上最高挑线周围的序列,鉴定出细胞色素P450(CYP703A2),携带固定在雄性不育亲本中的有害替换(R/Q)。围绕这个SNP开发了一个dCAPS标记,允许区分人群中的MS和MF基因型,适用于植物育种程序中的应用。通过同源性建模生成蛋白质的3D模型,揭示突变的氨基酸是对蛋白质折叠至关重要的高度保守基序的一部分。